Fix reporting refused connections with StreamSelectLoop on Windows #208
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The underlying `epoll_wait()` reports `EPOLLOUT|EPOLLERR|EPOLLHUP` on the affected file descriptor, which `ext-uv` emits as an error code `EBADF` with no events attached. We explicitly re-enable all active events on this error event to invoke the writable listener for this condition to match other event loop implementations and successfully detect this as a refused connection attempt. All tests are now green.
WyriHaximus
approved these changes
Dec 31, 2019
We do not usually use or expose the `exceptfds` parameter passed to the underlying `select`. However, Windows does not report failed connection attempts in `writefds` passed to `select` like most other platforms. Instead, it uses `writefds` only for successful connection attempts and `exceptfds` for failed connection attempts. See also https://docs.microsoft.com/de-de/windows/win32/api/winsock2/nf-winsock2-select We work around this by adding all sockets that look like a pending connection attempt to `exceptfds` automatically on Windows and merge it back later. This ensures the public API matches other loop implementations across all platforms (see also test suite or rather test matrix). Lacking better APIs, every write-only socket that has not yet read any data is assumed to be in a pending connection attempt state.
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jsor
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Dec 31, 2019
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We do not usually use or expose the
exceptfdsparameter passed to theunderlying
select. However, Windows does not report failed connectionattempts in
writefdspassed toselectlike most other platforms.Instead, it uses
writefdsonly for successful connection attempts andexceptfdsfor failed connection attempts. See alsohttps://docs.microsoft.com/de-de/windows/win32/api/winsock2/nf-winsock2-select
We work around this by adding all sockets that look like a pending
connection attempt to
exceptfdsautomatically on Windows and merge itback later. This ensures the public API matches other loop
implementations across all platforms (see also test suite or rather test
matrix). Lacking better APIs, every write-only socket that has not yet
read any data is assumed to be in a pending connection attempt state.
Resolves #206
Builds on top of #205 and #207 (see last commit to omit unrelated changes)